1. Technical Field
The present invention relates to a mounting substrate and a method of manufacturing the mounting substrate.
2. Description of the Related Art
In accordance with the trends towards higher performance in an electronic component, the package is being produced in smaller sizes and higher densities. This may require higher densities in the mounting substrate, i.e. the interposer, which connects the chip with the main board in a package. Examples of mounting methods currently used in a high-density package include wire bonding and flip bonding. In cases where the number of input/output terminals per unit area is increased, flip bonding can be more desirable, due to advantages in terms of cost, etc.
FIG. 1A is a cross sectional view of a flip chip ball grid array (FCBGA) structure according to the related art, and FIG. 1B is a magnified view of a portion of FIG. 1A. Referring to the drawings, a chip 100 may be electrically connected with the bonding pads 111 by way of bumps 113. The bonding pads 111 may be electrically connected with a circuit (not shown) formed on the insulating substrate. This circuit may be electrically connected with the solder balls 140. The solder balls 140 may be positioned between the insulating substrate 110 and the main board to provide electrical connection between the chip 100 and the main board.
The bonding pads 111 may be formed on one side of the insulating substrate 110. The bonding pads 111 may be formed by a method of forming apertures in a layer of solder resist 112 and performing plating with a conductive material. In this case, however, tolerances in the plating process can cause tolerances in the heights of the bonding pads 111. Then, if a screen-printing method is used to form the bumps 113, the bumps 113 may not be electrically connected with the chip if an insufficient amount of solder is printed. Also, the process of forming the layer of solder resist 112, forming an adhesive or underfill layer 130 and forming the apertures is a complicated process, which may not only require high precision but also increase costs.